Utilizing Hydrothermal Processing to Align Structure and In Vitro Digestion Kinetics between Three Different Pulse Types

Abstract

Processing results in the transformation of pulses’ structural architecture. Consequently, digestion is anticipated to emerge from the combined effect of intrinsic (matrix-dependent) and extrinsic (processed-induced) factors. In this work, we aimed to investigate the interrelated effect of intrinsic and extrinsic factors on pulses’ structural architecture and resulting digestive consequences. Three commercially relevant pulses (chickpea, pea, black bean) were selected based on reported differences in macronutrient and cell wall composition. Starch and protein digestion kinetics of hydrothermally processed whole pulses were assessed along with microstructural and physicochemical characteristics and compared to the digestion behavior of individual cotyledon cells isolated thereof. Despite different rates of hardness decay upon hydrothermal processing, the pulses reached similar residual hardness values (40 N). Aligning the pulses at the level of this macrostructural property translated into similar microstructural characteristics after mechanical disintegration (isolated cotyledon cells) with comparable yields of cotyledon cells for all pulses (41–62%). We observed that processing to equivalent microstructural properties resulted in similar starch and protein digestion kinetics, regardless of the pulse type and (prolonged) processing times. This demonstrated the capacity of (residual) hardness as a food structuring parameter in pulses. Furthermore, we illustrated that the digestive behavior of isolated cotyledon cells was representative of the digestion behavior of corresponding whole pulses, opening up perspectives for the incorporation of complete hydrothermally processed pulses as food ingredients.

Studying semi-dynamic digestion kinetics of food: Establishing a computer-controlled multireactor approach

“…Around 92-96% of all starch was hydrolyzed after 2h of small intestinal phase (Figure 2D, Table 3). This is line with previous research on diverse pulse types (Edwards et al, 2020;Gwala, Pallares Pallares, Pälchen, Hendrickx, & Grauwet, 2020;Pälchen et al, 2022).…”

“…A starch hydrolysis of 81-93% was reached after 2h of small intestinal digestion. This is again in line with previous static studies on diverse pulse types (Edwards, Maillot, Parker, & Warren, 2018;Gwala et al, 2020;Pälchen et al, 2022;Rovalino-Córdova, Fogliano, & Capuano, 2019).…”

“…The acid hydrolysis these samples underwent, further released free -amino groups allowing an easier interpretation of the amount of (un)digested protein (Pälchen et al, 2021). This amount is in line with other work performed on pulses at the same research unit (Gwala et al, 2020;Pälchen et al, 2022). Furthermore, this value also indicates that proteolysis is not yet complete, which could also be anticipated as the digestion kinetics did not reach the plateau at the end of the simulation (Figure 6A).…”

Strategic choices for in vitro food digestion methodologies enabling food digestion design

“…Applying a kinetic approach, in vitro studies focusing on lipid digestion elucidated the effect of emulsion stability on lipid digestion (Verkempinck, Salvia-Trujillo, Moens, Charleer, et al, 2018), and even postulated a plausible reaction mechanism for lipolysis (Infantes-Garcia et al, 2021). In the field of macronutrient digestion in pulses, a strong relation between thermal processing time, food structure (hardness), cell wall properties, and starch and protein digestion kinetics could be established (Duijsens et al, 2021;Pälchen et al, 2022).…”

How Cooking Time Affects In Vitro Starch and Protein Digestibility of Whole Cooked Lentil Seeds versus Isolated Cotyledon Cells

“…Most commonly, since individual cotyledon cells can be considered a representative fraction of disintegrated cooked pulse seeds, isolated cotyledon cells (ICC) are considered [20][21][22][23][24][25][26][27][28][29][30]. Since this approach entails the omission of certain fractions (such as cell clusters, fiber-rich seed coat material, and ruptured cells), it can be considered a reductionist approach [30,31]. The study of ICC fractions revealed a positive correlation between the applied cooking time and the starch and protein digestion rate and extent of isolated of black beans, common beans (Phaseolus vulgaris), and Bambara groundnut (Vigna subterranea) [31][32][33].…”